Quenching Studies of a Gold-Silver Alloy

The electrical resistance of gold—1.2 atomic percent silver samples was measured after quenching in the range 500° to 950°C. The resulting increase in resistivity immediately after the quench, $\Delta {\rho }_Q$, is described by the relation $\Delta {\rho }_Q=A\exp (-\frac{{E_f}^a}{k{T}_Q})$, where $A$ is (7.6±1.3)×${10}^{-4\mathrm{}}$ ohm-cm; ${E_f}^a$, the apparent formation energy equals (1.01±0.03) ev. From the experimental limits of error for the formation energy in pure gold, an upper limit of 0.1 ev was established for the binding energy between lattice vacancies and the solute atoms. The recovery of quenched-in resistivity was determined in the course of annealing between 50° and 84°C following a quench from 700°C. The slope intersection method gave an activation energy of 0.85±0.05 ev for the recovery of the quenched-in resistivity. The extra resistivity increased upon annealing by 8% and then annealed at a rate 30% to 40% less than that which has been observed for pure gold. The recovery behavior was interpreted in terms of vacancy-impurity complexes. A corresponding binding energy of 0.05 ev was obtained.